Metal underbody construction



Aug. 9, 1938, 1.. s. BOEHNER METAL UNDERBODY CONSTRUCTION 3 Sheets-Sheet 1 Filed Jur le 15, 1956 Cudu /Zy 6. Baa/me t 1938. L. a. BOEHNER 2,126,607

HETAL UNDERBODY CONSTRUCTION FiIed June 13, 1936 s Sheets-Sheet 2 Elma/11M Lida/Z9 (i. Beeline 0 Aug. 9, 1938. BQEHNER 2,126,607

METAL UNDERBODY CONSTRUCTION I Filed June 13, 1936- 3 Sheets-Sheet 3 a ,(zlduriq 6 Eveline b Patented Aug. 9, 1938 UNITED STATES PATENT OFFICE METAL UNDERBODY CONSTRUCTION ware Application June 13, 1936, Serial No. 85,023 In Germany November 9, 1935 13 Claims. (cl. 280-106) The invention relates to the construction of a sub-frame combining in a single unit the structure of the usual chassis and body underframe.

In the prior art the advantages of a common frame as well as the dimculties in the production of such a frame are recognized, but it is believed desirable to repeat that the essential advantages of the common frame consist in its light weight and its low center of gravity, while the dimculties in construction arise from the fact that the front part of the sub-frame (which carries the engine) must be made much narrower than the middle part. The middle part must have the same width as the body because only in having a wide middle is it possible to build a short and easily steered car without limiting the space for the passengers. If the front part of the sub-frame is greatly narrowed, the stifiness, not only of the sub-frame but also of the entire frame, suffers to an extraordinary degree. According to the prior methods of construction of unitary chassis and body frames, a weakening of the moments of resistance of the different girders or parts has been compensated by an increase in weight or thickness of metal. But this method takes from the unitary frame one of its main advantages, namely, low weight. Thus, the problem arises of compensating for the small degree of stiffness of the sub-frame, caused by the narrowing of the front part of the sub-frame, by a thorough detailed study of the design of the sub-frame. The redesigned frame must not increase the weight of the unitary sub-frame as compared with the prior art frame that has not been narrowed. 5 In the prior art solutions are given for the production of a sub-frame which is stiffened against distortion, bending and shifting. The basis of these solutions has been the idea of making the frame out of a large number of small and simple iron shapes-in order to save large and expensive dies and presses.- While the production of the separate parts was thus made simple and cheap, the assembly of the sub-frame, however, on account of the multiplicity of the parts, remained comparatively expensive. According to the present invention, in order to simplify and cheapen the assembly, instead of the many small parts.

of the prior art a few large pressed parts are used for the construction of the sub-frame. 0n the other hand, in order not to cause excessive increase in the cost of presses, the number of the large pressed parts required is held as low as possible and sub-frames that are stiifened against bending, distortion and shifting are produced merely by the form that is given to the pressed According to the invention the middle frame portion of the sub-frame, that is, that part which has the same width as the body, is constructed substantially of two pressed sheets which are formed at their edges into a channel or a U-shaped. profile. The sheets are laid on each other and welded together in such a way that the U-shaped parts of the two sheets mate and form at the edge of the frame a box-shaped girder of high resistant properties. On account of the low center of gravity of the body, a tunnel for the propeller shaft is necessary, and transverse walls placed at right angles to this tunnel are connected with the tunnel and the sheet metal frame in order to increase the rigidity of the frame against torsion. In the construction of the new sub-frame special consideraion has been given to making the lower-side of the frame as smooth as possible, the purpose of this structure being to obtain a favorable airflow or decrease in air resistance. Care has also been taken to keep the ground clearance low by avoiding having any parts projecting downward from the sub-frame. Moreover, the frame is constructed in such a way that dust, water or mud cannot penetrate into the body. 0n the drawings Figure 1 is a plan view of the sub-frame. Figure 2 is a side view. Figures 3, 4, and 5 are longitudinal sections through the-sub-frame on the lines 3-3, 4-4, and 5-5 of Figured.

Figures 6 to 9 inclusive are transverse sections through the sub-frame on the lines 8-4, 'l-'l, 8-8, and 9-9 of Figure 1.

Figures 10, 11, and 12 are transverse sections through the sub-frame on the lines |0--l0, ll--H, and 12-42 of Figure 3.

Figures 13 and 14 are transverse sections through the sub-frame on the lines Il-I3 and 14-44 of Figure 1.

Figure 15 is a longitudinal section on line ll-l5 ofFigui-e 1..

Figure 16 is a perspective view of the subframe, seen from above.

As already indicated, the middle part of the sub-frame consists of a lower sheet I and an upper sheet 2. As is apparent from the detailed cross sectional views in Figures 6, '7, 8, and 9, the lower pressing I has pressed out or formed along its longitudinal edges a U-shaped profile or channel 3 which decreases in depth from rear to front. The upper sheet 2 consists of two Wings 211 and 2b, which have a U-shapedprofile or channel 4 running around their edges and formed by stamping or pressing. The sheet 2 has a central cut-out which forms the wings, and where the wing edges face each other on the longitudinal center line of the car no channels are provided. The channel 3 has the lateral flange 3a and the channel 4 has the lateral flange 4a mating with the flange 3a and welded thereto.

As shownin Figure 1, both the upper and the lower sheetsare indented at the front end at the middle as shown at A in order to provide a free or an open space for the mounting of the engine block. At this point the U-shaped sections of the two portions 2a and 2b of the sheet are integral and combine into a single profile 5 which extends inwardly of the frame and ends at the first transverse bracing H of the frame.

From the endof the profile 5 and rearwardly of the bracing II, the edges of the two sheets 20. and 2b are bent upwardly as at 6 and then inwardly flanged as at 6a,. the flanges being connected throughout their entire length to complemental flanges Ia of an arched tunnel I to form a box section, so that a box girder with high resistance properties is produced at the middle of the frame. As is shown in Figures 1 and 4, the tunnel I is welded at its front end at 117 to the profile 5 and at its rear end to the adjacent parts of the frame. Where the U- shaped profiles of the upper sheets are not made into a box girder by a corresponding U-shaped profile of the lower sheet, the same efi'ect is accomplished by the flat lower. sheet itself. The result is that the middle part of the frame consists of three longitudinal girders, that is, the two girders 3-4 at the sidesand the tunnel I, and two transverse girders of box section; that is, the girders 34 at the ends.

As is seen from the cross sectional view, the profile 4 of the upper sheet 2 is deeper than the profile 3 of the lower sheet I. In order to obtain a better flowing of the material in the pressing oi the sheets 2a and 2b, rectangular pieces 8 are cut out of the upper sheet; at these points the lower sheet which now has to carry all the load, is stiffened by beads 8a.

The longitudinal extension girders 9 of the front part of the frame pass through the box section formed by the channel or profile 4 in the wings 2a and 2b at the front end of the frame. These girders taper or become smaller gradually toward the rear. Beyond the place of entry of the girders 9, U-shaped profiles IO, gradually tapering or decreasing in height toward the rear, are pressed out of the sheets 2a and 2b. These channels I0 run parallel with the longitudinal axis of the frame and are connected with the profile 4 and form shoes for the reception of the longitudinal girders 9 which are welded thereto. irders 9 pass, is cut away to receive the girders and the-edges 9a at the cut-away part welded to the flanges 9b of the girders. If desired, channels corresponding to the channels I0 may bepressed upwardly from the sheet I into the channels III to form the shoe for the girders.

The longitudinal girder 9 at its foremost part has an open box-shape (Figure 10) Then, as is seen from Figures 2' and 11, a sheet II is welded to the under side of the girder. A short distance from the girder end the sheet I I takes a U -shaped profile (Figure 12). and is welded to the .ianges of the longitudinal girder 8 and produces a box- The lower sheet I, where theshaped profile of high resistance properties. A plate I la is preferably placed between the upper and. lower channels of the girder 9 the plate commencing immediately before the girder 8 enters the channel 4 and ending at the end of the girder.

Figure 1 shows how the forces are transmitted from the front frame to the middle part of the frame. It is essential that the forces which pass from the middle part of the frame to the rear part of the frame and then to the rear axle, be offered further resistance, that is, it is desirable that the rear part of the frame, as far as possible, be given rigidity to resist bending and torsion. The fulfilling of this requirement at the rear part of the frame offers constructional difiiculties for the reason that the low position of the middle part of the frame with relation to the axles of the car makes it necessary to curve the frame upward or provide it with a kick-up, so that it may extend up over the axle.

The rear part of the frame consists of an arched sheet I2 (Figure 5) which forms a continuation of sheet I and has a deep channel or U-shaped profile I2a at its rear and lateral edges. By means of the channel or U-shaped profiles I3 the profiles IZa are supplemented in such a way as to make welded closed box girders. The height of the channel or profile I3 decreases gradually toward the rear of the frame. At the rear end of the frame the channel I2a is welded to a cover plate I4. Intermediate its length at a plurality of points the rear sheet I2 is provided with transverse channels or ribs IZb (Figures 5, 14, and 15) which are covered by channel strips I2c welded thereto to form box sections. At the edge of the sheet I2 the strips I2c are flattened as at I2d and the fiat end welded between the channels I2a and I3. Additional pressings I29! and He may be provided for strengthening purposes.

The channels I3 are divided or forked at the front end into two channels Hit and Hill, connected by the strengthening ribs I30 and the flat part I311. The channel I3a follows the channel I2a while the channel I3b is directed inwardly and is welded to the sheet I2, while a channel rib I3 1 formed in the sheet I 2 mates with the ribs I3c to form a box-sectioned construction. The sheet I2, the channels I2a, as well as the channels I31: and I3b are lap-welded to the sheets I and 2 and to the channels 3 and 4, the lap welds being coincident with the points where the front ends of the rear springs are attached. The lapping gives the great strength necessary at this point.

Bosses I5 are pressed downward in the sheet I2 below the position for the rear seat, and between them there is an arched part I S which is lap welded at I 6a to the rear end of tunnel I. This connection Ilia increases the stiffness of the rear part of the frame and of the sub-frame as a whole to a very considerable degree.

The above description of the sub-frame shows the passage of the forces or the transmission of the forces to the rear part of the frame or vice versa. Shocks occurring in collisions are transmitted from the longitudinal members 9 to the box-shaped edge girders and to the tunnel I, and then to the rear longitudinal girders I2a.l3, the transmission of the forces being effected or transmitted from the tunnel through the channels l3b which extend over toward the tunnel. Forces acting vertically downward and combined at the center of the frame are transmitted through the box-shaped edge girders and through the tunnel made in the form of a girder, either'directly or through the vehicle. body to the points where the springs are attached.

In order to make the sub-frame rigid, not only I against bending and displacement or shifting but fully resistant to torsion as well, several addibox-shaped section of high resistance properties.

The rib I1 is highest at the middle where it passes over the tunnel I and tapers gradually towards both ends where it has substantially the same height as the channel I. As shown in Figures 3 and 4, the sheet is carried over the tunnel 1, so that a continuous fiow of forces may be transmitted in the transverse direction of the frame. The same idea is carried out in the other transverse stiffening members. Immediately below the rib I] the sheet 2 is provided with a rib llc.

Also the heel plate and rear seat support l8 in the rear has been given a box-shaped profile,

the flanges I of which are welded to the upper sheets 2a and 2b, to the channel 4 and to the tunnel The heel plate l8 comprises the channel member Mia and the arch lBb welded to each other and to the adjacent parts. Here also the sheet is carried over the tunnel I in order to prevent any interruption in the transmission of forces. At the heel plate ends triangular flanged plates l8d are welded by their flanges to the plate ends and to the channels l3b. If desired, these plates IBd may be the bent-over ends of the channel member Illa. Pressed or indented portions I82 to stiffen the channel |8a may optionally be used. The same idea is found also in the semi-circular rib l9 formed in the upper sheets 2a and 2b at the middle part of the frame. As shown in Figures 4 and 8, the sheets i and 2 have parts at their middle cut for the width of the tunnel, but in order to obtain an uninterrupted transmission of forces for the transverse stiffening is, a semi-circular sheet 20 is welded below to bridge the break caused by the tunnel.

The lower sheet I is downwardly arched at its rear end under' the tunnel as shown at 22 in Figures 2 and 4 to accommodate the propeller shaft. The rearmost part of the sheet I under the tunnel is split at its middle and flanged upwardly against the tunnel as shown at 23 in Figures 4 and 9.

I claim:

1. A unitary vehicle frame combining the chassis and the underframe of the body, said unitary frame consisting of a middle part the width of the vehicle body, a narrowed front part, and an arched rear part, said middle part com-' prising upper and lower sheets, a 'U-shaped profile or channel formed at the edge of each sheet, said sheets being welded together, said channels mating-with each other to form a box-shaped girder at the edge of the frame, said upper sheet consisting of two wing'parts having a space therebetween, upwardly flanged inner edges on said wings, and a tunnel welded to said flanges to form' a box-shaped girder.v

2. A unitary vehicle frame combining the chassis and the underframe of the body, said prising substantially two sheets, a U-shaped profile or channel formed at the edge of each sheet, said sheets being welded together, said channels mating with each other 'to form a box-shaped girder at the edge of the frame, and a tunnel centrally of the frame and welded to the wide part of the frame to form therewith a boxsectioned construction.

3. A unitary vehicle frame combining the chassis and the underframe of the body, said unitary frame consisting of amiddle part the width of the vehicle body, a narrowed front part, and an arched rear part, said middle part comprising substantially two sheets, a U-shaped profile or channel formed at the lateral edge of each sheet, said sheets being welded together, said channels mating with each other to form a box-shaped girder at the edge of theframe, said two sheets being indented at the front end at the right and left of the center line, U-shaped profiles orchannels in the upper sheet at the indented edge, said lower sheet being fiat at the front edge and closing the front edge channel to form a boxshaped section.

4. A unitary vehicle frame combining the chassis and the underframe of the body, said unitary frameconsisting of a middle part the width of the vehicle body, a narrowed front part, and an arched rear part, said middle part comprising susbtantially two sheets, a U-shaped profile or channel formed at the lateral edge of each sheet, said sheets being welded together, .said channels matingwith each other to form a box-shaped rder at the edge of the frame, longitudinal girders forming the front narrow part of the frame, U-shaped profiles or channels at the front end of the middle part of the frame, said lastnamed channels havingopenings, and U-shaped profiles of decreasing height pressed out of the upper sheet and forming shoes for the ends of the longitudinal girders, said girders being welded in said shoes.

1 5. A unitary vehicle frame combining the chassis and the underframe of the body, said unitary frame consisting of a middle part the width of the vehicle body, a narrowed front part, and an arched rear part, said middle part comprising substantially two sheets, a U-shaped profile or channel formed at the edge of each sheet, said sheets being welded together, said channels mating with each other to form a box-shaped girder at the edge of the frame, said rear part of the frame consisting of an arched sheet, U-shaped profiles or channels at the edges of said arched rear sheet,- channels at the longitudinal edges of the arched sheet mating with the channels thereof to form box-shaped girders at the longitudinal edges of the sheets.

6. A unitary vehicle frame combining the chassis and the underframe of the body, said unitary frame consisting of a middle part the width of the.

vehiclebody, a narrowed front part, and an arched rear part, said middle part comprising substantially two sheets, a U-shaped profile or channel formed at the edge of each sheet, said sheets being welded together, said, channels mating with each other to form a box-shaped girder at the edge of the frame, said rear part of the frame consisting of an arched sheet, U-shaped profiles or channels at the edges of said arched sheet, channels at the longitudinal sides of the arched sheet welded to and mating with channels thereof to form box-shaped girders at the longitudinal edges of the sheets, said channels at the longitudinal edges 'of the arched sheet being iorked into two branches, a central longitudinal tunnel, one arm of the fork extending in the direction of the tunnel, the other arm being welded to the U-shaped profiles of the .upper sheet.

7. A unitary vehicle frame combining the chassis and the underframe of the body, said unitary frame consisting of a middle part the width of the vehicle body, a narrowed front part, and an arched rear part, said middle part comprising substantially two sheets, a U-shaped profile or channel formed at the edge of each sheet, said sheets being welded together, said channels mating with each other to form a box-shaped girder at the edge of the frame, said rear part of the frame consisting of an arched sheet, U-shaped profiles or channels at the edges of said arched sheet, channels at the longitudinal sides of the arched sheet mating with and welded to the channels thereof to form box-shaped girders at the longitudinal edges of the sheets, the connection between the middle part of the frame and the archedrear sheet being effected by lapping and the vehicle body, a narrowed front part, and an arched rear part, said middle part comprising substantially two sheets, a U-shaped profile or channel formed at the edge of each sheet, said sheets being welded together, said channels mating with each other to form a box-shaped girder at the edge of the frame, a tunnel welded to the middle part of the frame, said rear part of the frame consisting of an arched sheet, U-shaped profiles or channels at the edges 'of said arched sheet, channels at the longitudinal edges of the arched sheet mating with and welded to the channels thereof to form box-shaped girders at the longitudinal edges of the sheets, said sheet being arched downward at its sides under the seat and arched upward substantially on the center line of the car between the seats, said arch conforming in shape to the profile of the tunnel andwelded to the tunnel.

9; A unitary vehicle frame combining the chassis and the underframe of the body, said unitary frame consisting of a middle part' the width of the vehicle body, a narrowed front 'part, and an arched rear part, said middle part comprising substantially two sheets,'a U-shaped profile or channel formed at the edge of each sheet, said sheets being welded together, said channels mating with each other to form a box-shaped girder at the edge of the frame, a tunnel at the center of the frame, a transverse brace at the middle part of the frame, said transverse brace being secured to the upper of the two sheets and to the tunnel to form a box-shaped cross sectional construction,

said transverse brace extending above the tunnel.

10. A unitary vehicle frame combining the chassis and the underframe of the body, said unitary frame consisting of a middle part the width of the vehicle body, a narrowed front part, and an arched rear part, said middle part comprising substantially two sheets, a U-shaped profile or channel formed at the edge of each sheet, said sheets being welded together, said channels mating with each other to form a box-shaped girder at the edge of the frame, stiffening arches formed in the individual sheets of the middle part of the frame, said sheets having a cut-out part, a tunnel bridging the upper side of the cut-out part. and formed sheets bridging the break in the cutout from below.

11. In a unitary vehicle frame combining the chassis and the underframe of the body, said frame consisting of a middle part, a front part and a rear part, said middle part comprising a plurality of metal sheets secured together, mating upwardly and downwardly directed channels on the sheets to form box girder constructions at the edges of the sheets, a box girder construction at the front edge of the sheets, transverse bracing means to reinforce the sheets, a longitudinal tunnel secured to the middle of the frame, a plurality of transverse braces welded to the middle frame part, said braces secured to and extending over the tunnel.

12. In a unitary vehicle frame combining the chassis and the underframe of the body, said frame consisting of a middle part, a front part and a rear part, said middle part comprising a plurality of metal sheets secured together, mating upwardly and downwardly directed channels on the sheets to form box girder constructions at the edges of the sheets, a transverse brace at the forward part of the middle frame part, and a transverse brace at the rear of the middle frame part, said transverse braces extending the full width of the frame and being welded thereto.

13. In a unitary vehicle frame combining the chassis and the underframe of the body, said frame consisting of a middle part, a front part and a rear part, said middle part comprising a plurality of metal sheets secured together, mating upwardly and downwardly directed channels on the sheets to form box girder constructions at the edges of the sheets, a transverse brace at the forward part of the middle frame part, a transverse brace at the rear of the middle frame part, transverse braces extending the full width of the frame and being welded thereto, and a channel formed in the upper sheet between the two transverse braces and extending transversely of the frame and being closed at its underside by the lower sheet.

LUDWIG G. BOEHNER. .0

, $4 H CERTIFICATElOF COR'REC'I'IIK HT Patent-No, 2,126,607 7 August 9, 1958.,

' LUDWIG Go BOEHNERQ It is hereby certified that error aippears in. the printed specification of theabove numbered. pateht requiringoor-reotioh as follows Page 5 first column, line 1 1;, afterthe word-"out" insert out; page )4, second column,

line 53,- claim 15, befoi'e "transverse" insert saidyand that the said Let ters Patent should be read with this correction therein that the same may oonform to the record of the casein the Patent Office,

Signed and sealed this 25th day of October, A. D. 1938a Henry Van Aredvale '(seal) Aeting" Commissioner of Patents, 

